UCL News


Protein enables heart to heal itself

8 December 2006

A team led by Dr Paul Riley (UCL Institute of Child Health) has published research in 'Nature' demonstrating that a protein can teach adult heart cells to heal.

Emerging cells on the outside of the cardiac muscle  

The research shows that the protein thymosin ß4 can stimulate blank cells with the potential to develop into any cell type to move from the outermost layer of an adult heart deeper within the organ to rebuild blood vessels and nourish tissue. The research was funded by the British Heart Foundation and the Medical Research Council.

Dr Riley's team made the discovery by breeding mice without thymosin ß4, a protein that was already known to reduce the loss of muscle cells after a heart attack. As a result, the mice's hearts failed to develop normally, showing early signs of tissue loss and poor development of blood vessels. Once cells from the outermost layer of the hearts had been treated with the protein, they had the potential to create healthy heart tissue.

The findings disprove the prevailing belief that no heart cells have the capacity to regenerate tissue. Up until now, scientists thought that the only blank or 'progenitor' cells that could help repair the heart originated in bone marrow.

"If we can figure out how to direct the progenitor cells using thymosin ß4, there could be potential for therapy based on patients' own heart cells," said Dr Riley. "This approach would bypass the risk of immune system rejection, a major problem with the use of stem cell transplants from another source. And it has the added benefit that the cells are already located in the right place, within the heart itself."

Colonies of cells stimulated by thymosin ß4

Professor Jeremy Pearson, Associate Medical Director of the British Heart Foundation, warmly welcomed the discovery: "These results are important and exciting. Dr Riley's group have taken a large step towards practical therapy to encourage damaged hearts to repair themselves, a goal that researchers are urgently aiming for."

Professor Colin Blakemore, Chief Executive of the Medical Research Council, also commended the work of Dr Riley's team: "Finding out how this protein helps to heal the heart offers enormous potential in fighting heart disease, which kills more than 105,000 people in the UK every year. This is an excellent example of the way in which first-class research, at the most basic molecular level, can produce opportunities for translation into innovative treatments that should help patients and improve their lives."

To read the paper in full, follow the links at the bottom of this article.

Image 1: Large colonies of cells from adult heart explants stimulated by thymosin ß4

Image 2: Clockwise from top left: emerging cells on the outside of the cardiac muscle (blue box). Following migration, cells undergo differentiation into a) fibroblasts - connective wound-healing tissue (yellow box); b) endothelial cells - cells that line blood vessels (red box) and c) smooth muscle cells (green box)